
<!DOCTYPE HTML>
<html lang="" >
    <head>
        <meta charset="UTF-8">
        <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
        <title>HTML5画布移植（Porting from HTML5 Canvas） · GitBook</title>
        <meta http-equiv="X-UA-Compatible" content="IE=edge" />
        <meta name="description" content="">
        <meta name="generator" content="GitBook 3.2.3">
        
        
        
    
    <link rel="stylesheet" href="../gitbook/style.css">

    
            
                
                <link rel="stylesheet" href="../gitbook/gitbook-plugin-highlight/website.css">
                
            
                
                <link rel="stylesheet" href="../gitbook/gitbook-plugin-search/search.css">
                
            
                
                <link rel="stylesheet" href="../gitbook/gitbook-plugin-fontsettings/website.css">
                
            
        

    

    
        
    
        
    
        
    
        
    
        
    
        
    

        
    
    
    <meta name="HandheldFriendly" content="true"/>
    <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
    <meta name="apple-mobile-web-app-capable" content="yes">
    <meta name="apple-mobile-web-app-status-bar-style" content="black">
    <link rel="apple-touch-icon-precomposed" sizes="152x152" href="../gitbook/images/apple-touch-icon-precomposed-152.png">
    <link rel="shortcut icon" href="../gitbook/images/favicon.ico" type="image/x-icon">

    
    <link rel="next" href="../particle_simulations/" />
    
    
    <link rel="prev" href="canvas_paint.html" />
    

    </head>
    <body>
        
<div class="book">
    <div class="book-summary">
        
            
<div id="book-search-input" role="search">
    <input type="text" placeholder="Type to search" />
</div>

            
                <nav role="navigation">
                


<ul class="summary">
    
    

    

    
        
        
    
        <li class="chapter " data-level="1.1" data-path="../">
            
                <a href="../">
            
                    
                    Introduction
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.2" data-path="../meet_qt_5/">
            
                <a href="../meet_qt_5/">
            
                    
                    Qt5概述
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.2.1" data-path="../meet_qt_5/preface.html">
            
                <a href="../meet_qt_5/preface.html">
            
                    
                    序
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.2.2" data-path="../meet_qt_5/qt5_introduction.html">
            
                <a href="../meet_qt_5/qt5_introduction.html">
            
                    
                    Qt5介绍
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.2.3" data-path="../meet_qt_5/qt_building_blocks.html">
            
                <a href="../meet_qt_5/qt_building_blocks.html">
            
                    
                    Qt构建模块（Qt Building Blocks）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.2.4" data-path="../meet_qt_5/qt_project.html">
            
                <a href="../meet_qt_5/qt_project.html">
            
                    
                    Qt项目（Qt Project）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.3" data-path="../get_start/">
            
                <a href="../get_start/">
            
                    
                    开始学习（Get Start）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.3.1" data-path="../get_start/qt5installing_qt_5_sdk.html">
            
                <a href="../get_start/qt5installing_qt_5_sdk.html">
            
                    
                    安装Qt5软件工具包（Installing Qt 5 SDK）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.3.2" data-path="../get_start/hello_world.html">
            
                <a href="../get_start/hello_world.html">
            
                    
                    你好世界（Hello World）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.3.3" data-path="../get_start/application_types.html">
            
                <a href="../get_start/application_types.html">
            
                    
                    应用程序类型（Application Types）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.3.4" data-path="../get_start/summary.html">
            
                <a href="../get_start/summary.html">
            
                    
                    总结（ Summary）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.4" data-path="../qt_creator_ide/">
            
                <a href="../qt_creator_ide/">
            
                    
                    Qt Creator集成开发环境（Qt Creator IDE）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.4.1" data-path="../qt_creator_ide/the_user_interface.html">
            
                <a href="../qt_creator_ide/the_user_interface.html">
            
                    
                    用户界面（The User Interface）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.4.2" data-path="../qt_creator_ide/qtregistering_your_qt_kit.html">
            
                <a href="../qt_creator_ide/qtregistering_your_qt_kit.html">
            
                    
                    注册你的Qt工具箱（Registering your Qt Kit）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.4.3" data-path="../qt_creator_ide/managing_projects.html">
            
                <a href="../qt_creator_ide/managing_projects.html">
            
                    
                    项目管理（Managing Projects）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.4.4" data-path="../qt_creator_ide/using_the_editor.html">
            
                <a href="../qt_creator_ide/using_the_editor.html">
            
                    
                    使用编辑器（Using the Editor）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.4.5" data-path="../qt_creator_ide/locator.html">
            
                <a href="../qt_creator_ide/locator.html">
            
                    
                    定位器（Locator）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.4.6" data-path="../qt_creator_ide/debugging.html">
            
                <a href="../qt_creator_ide/debugging.html">
            
                    
                    调试（Debugging）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.4.7" data-path="../qt_creator_ide/shortcuts.html">
            
                <a href="../qt_creator_ide/shortcuts.html">
            
                    
                    快捷键（Shortcuts）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.5" data-path="../quick_starter/">
            
                <a href="../quick_starter/">
            
                    
                    QML快速入门（Quick Starter）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.5.1" data-path="../quick_starter/qmlqml_syntax.html">
            
                <a href="../quick_starter/qmlqml_syntax.html">
            
                    
                    QML语法（QML Syntax）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.5.2" data-path="../quick_starter/basic_elements.html">
            
                <a href="../quick_starter/basic_elements.html">
            
                    
                    基本元素（Basic Elements）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.5.3" data-path="../quick_starter/compontents.html">
            
                <a href="../quick_starter/compontents.html">
            
                    
                    组件（Compontents）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.5.4" data-path="../quick_starter/simple_transformations.html">
            
                <a href="../quick_starter/simple_transformations.html">
            
                    
                    简单的转换（Simple Transformations）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.5.5" data-path="../quick_starter/positioning_element.html">
            
                <a href="../quick_starter/positioning_element.html">
            
                    
                    定位元素（Positioning Element）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.5.6" data-path="../quick_starter/layout_items.html">
            
                <a href="../quick_starter/layout_items.html">
            
                    
                    布局元素（Layout Items）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.5.7" data-path="../quick_starter/input_element.html">
            
                <a href="../quick_starter/input_element.html">
            
                    
                    输入元素（Input Element）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.5.8" data-path="../quick_starter/advanced_techniques.html">
            
                <a href="../quick_starter/advanced_techniques.html">
            
                    
                     高级用法（Advanced Techniques）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.6" data-path="../fluid_elements/">
            
                <a href="../fluid_elements/">
            
                    
                    动态元素（Fluid Elements）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.6.1" data-path="../fluid_elements/animations.html">
            
                <a href="../fluid_elements/animations.html">
            
                    
                    动画（Animations）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.6.2" data-path="../fluid_elements/states_and_transitions.html">
            
                <a href="../fluid_elements/states_and_transitions.html">
            
                    
                    状态与过渡（States and Transitions）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.6.3" data-path="../fluid_elements/advanced_techniques.html">
            
                <a href="../fluid_elements/advanced_techniques.html">
            
                    
                    高级用法（Advanced Techniques）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.7" data-path="../model-view-delegate/">
            
                <a href="../model-view-delegate/">
            
                    
                    模型-视图-代理（Model-View-Delegate）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.7.1" data-path="../model-view-delegate/concept.html">
            
                <a href="../model-view-delegate/concept.html">
            
                    
                    概念（Concept）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.7.2" data-path="../model-view-delegate/basic_model.html">
            
                <a href="../model-view-delegate/basic_model.html">
            
                    
                    基础模型（Basic Model）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.7.3" data-path="../model-view-delegate/dynamic_views.html">
            
                <a href="../model-view-delegate/dynamic_views.html">
            
                    
                    动态视图（Dynamic Views）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.7.4" data-path="../model-view-delegate/delegate.html">
            
                <a href="../model-view-delegate/delegate.html">
            
                    
                    代理（Delegate）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.7.5" data-path="../model-view-delegate/advanced_techniques.html">
            
                <a href="../model-view-delegate/advanced_techniques.html">
            
                    
                    高级用法（Advanced Techniques）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.7.6" data-path="../model-view-delegate/summary.html">
            
                <a href="../model-view-delegate/summary.html">
            
                    
                    总结（Summary）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.8" data-path="./">
            
                <a href="./">
            
                    
                    画布元素（Canvas Element）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.8.1" data-path="convenient_api.html">
            
                <a href="convenient_api.html">
            
                    
                    便捷的接口（Convenient API）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.8.2" data-path="gradients.html">
            
                <a href="gradients.html">
            
                    
                    渐变（Gradients）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.8.3" data-path="shadows.html">
            
                <a href="shadows.html">
            
                    
                    阴影（Shadows）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.8.4" data-path="images.html">
            
                <a href="images.html">
            
                    
                    图片（Images）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.8.5" data-path="transformation.html">
            
                <a href="transformation.html">
            
                    
                    转换（Transformation）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.8.6" data-path="composition_mode.html">
            
                <a href="composition_mode.html">
            
                    
                    组合模式（Composition Mode）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.8.7" data-path="pixels_buffer.html">
            
                <a href="pixels_buffer.html">
            
                    
                    像素缓冲（Pixels Buffer）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.8.8" data-path="canvas_paint.html">
            
                <a href="canvas_paint.html">
            
                    
                    画布绘制（Canvas Paint）
            
                </a>
            

            
        </li>
    
        <li class="chapter active" data-level="1.8.9" data-path="html5porting_from_html5_canvas.html">
            
                <a href="html5porting_from_html5_canvas.html">
            
                    
                    HTML5画布移植（Porting from HTML5 Canvas）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.9" data-path="../particle_simulations/">
            
                <a href="../particle_simulations/">
            
                    
                    粒子模拟（Particle Simulations）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.9.1" data-path="../particle_simulations/concept.html">
            
                <a href="../particle_simulations/concept.html">
            
                    
                    概念（Concept）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.9.2" data-path="../particle_simulations/simple_simulation.html">
            
                <a href="../particle_simulations/simple_simulation.html">
            
                    
                    简单的模拟（Simple Simulation）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.9.3" data-path="../particle_simulations/particle_parameters.html">
            
                <a href="../particle_simulations/particle_parameters.html">
            
                    
                    粒子参数（Particle Parameters）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.9.4" data-path="../particle_simulations/directed_particle.html">
            
                <a href="../particle_simulations/directed_particle.html">
            
                    
                    粒子方向（Directed Particle）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.9.5" data-path="../particle_simulations/particle_painter.html">
            
                <a href="../particle_simulations/particle_painter.html">
            
                    
                    粒子画笔（Particle Painter）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.9.6" data-path="../particle_simulations/affecting_particles.html">
            
                <a href="../particle_simulations/affecting_particles.html">
            
                    
                    粒子控制（Affecting Particles）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.9.7" data-path="../particle_simulations/particle_group.html">
            
                <a href="../particle_simulations/particle_group.html">
            
                    
                    粒子组（Particle Group）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.9.8" data-path="../particle_simulations/summary.html">
            
                <a href="../particle_simulations/summary.html">
            
                    
                    总结（Summary）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.10" data-path="../shader_effect/">
            
                <a href="../shader_effect/">
            
                    
                    着色器效果（Shader Effect）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.10.1" data-path="../shader_effect/openglopengl_shader.html">
            
                <a href="../shader_effect/openglopengl_shader.html">
            
                    
                    OpenGL着色器（OpenGL Shader）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.10.2" data-path="../shader_effect/shader_elements.html">
            
                <a href="../shader_effect/shader_elements.html">
            
                    
                    着色器元素（Shader Elements）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.10.3" data-path="../shader_effect/fragement_shader.html">
            
                <a href="../shader_effect/fragement_shader.html">
            
                    
                    片段着色器（Fragement Shader）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.10.4" data-path="../shader_effect/wave_effect.html">
            
                <a href="../shader_effect/wave_effect.html">
            
                    
                    波浪效果（Wave Effect）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.10.5" data-path="../shader_effect/vertex_shader.html">
            
                <a href="../shader_effect/vertex_shader.html">
            
                    
                    顶点着色器（Vertex Shader）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.10.6" data-path="../shader_effect/curtain_effect.html">
            
                <a href="../shader_effect/curtain_effect.html">
            
                    
                    剧幕效果（Curtain Effect）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.10.7" data-path="../shader_effect/qtqt_graphicseffect_library.html">
            
                <a href="../shader_effect/qtqt_graphicseffect_library.html">
            
                    
                    Qt图像效果库（Qt GraphicsEffect Library）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.11" data-path="../multimedia/">
            
                <a href="../multimedia/">
            
                    
                    多媒体（Multimedia）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.11.1" data-path="../multimedia/playing_media.html">
            
                <a href="../multimedia/playing_media.html">
            
                    
                    媒体播放（Playing Media）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.11.2" data-path="../multimedia/sounds_effects.html">
            
                <a href="../multimedia/sounds_effects.html">
            
                    
                    声音效果（Sounds Effects）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.11.3" data-path="../multimedia/video_streams.html">
            
                <a href="../multimedia/video_streams.html">
            
                    
                    视频流（Video Streams）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.11.4" data-path="../multimedia/capturing_images.html">
            
                <a href="../multimedia/capturing_images.html">
            
                    
                    捕捉图像（Capturing Images）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.11.5" data-path="../multimedia/advanced_techniques.html">
            
                <a href="../multimedia/advanced_techniques.html">
            
                    
                    高级用法（Advanced Techniques）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.11.6" data-path="../multimedia/summary.html">
            
                <a href="../multimedia/summary.html">
            
                    
                    总结（Summary）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.12" data-path="../networking/">
            
                <a href="../networking/">
            
                    
                    网络（Networking）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.12.1" data-path="../networking/httpuiserving_ui_via_http.html">
            
                <a href="../networking/httpuiserving_ui_via_http.html">
            
                    
                    通过HTTP服务UI（Serving UI via HTTP）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.12.2" data-path="../networking/templating.html">
            
                <a href="../networking/templating.html">
            
                    
                    模板（Templating）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.12.3" data-path="../networking/httphttp_requests.html">
            
                <a href="../networking/httphttp_requests.html">
            
                    
                    HTTP请求（HTTP Requests）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.12.4" data-path="../networking/local_files.html">
            
                <a href="../networking/local_files.html">
            
                    
                    本地文件（Local files）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.12.5" data-path="../networking/restrest_api.html">
            
                <a href="../networking/restrest_api.html">
            
                    
                    REST接口（REST API）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.12.6" data-path="../networking/authentication_using_oauth.html">
            
                <a href="../networking/authentication_using_oauth.html">
            
                    
                    使用开放授权登陆验证（Authentication using OAuth）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.12.7" data-path="../networking/engine_io.html">
            
                <a href="../networking/engine_io.html">
            
                    
                    云服务（Engine IO）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.12.8" data-path="../networking/web_sockets.html">
            
                <a href="../networking/web_sockets.html">
            
                    
                    Web Sockets
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.12.9" data-path="../networking/summary.html">
            
                <a href="../networking/summary.html">
            
                    
                    总结（Summary）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.13" data-path="../storage/">
            
                <a href="../storage/">
            
                    
                    存储（Storage）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.13.1" data-path="../storage/settings.html">
            
                <a href="../storage/settings.html">
            
                    
                    配置（Settings）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.13.2" data-path="../storage/local_storage_-_sql.html">
            
                <a href="../storage/local_storage_-_sql.html">
            
                    
                    本地存储 - SQL（Local Storage - SQL）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.13.3" data-path="../storage/other_storage_apis.html">
            
                <a href="../storage/other_storage_apis.html">
            
                    
                    其它存储接口（Other Storage APIs）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.14" data-path="../dynamic_qml/">
            
                <a href="../dynamic_qml/">
            
                    
                    动态QML（Dynamic QML）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.14.1" data-path="../dynamic_qml/loading_components_dynamically.html">
            
                <a href="../dynamic_qml/loading_components_dynamically.html">
            
                    
                    动态加载组件（Loading Components Dynamically）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.14.1.1" data-path="../dynamic_qml/connecting_indirectly.html">
            
                <a href="../dynamic_qml/connecting_indirectly.html">
            
                    
                    间接连接（Connecting Indirectly）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.14.1.2" data-path="../dynamic_qml/binding_indirectly.html">
            
                <a href="../dynamic_qml/binding_indirectly.html">
            
                    
                    间接绑定（Binding Indirectly）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.14.2" data-path="../dynamic_qml/creating_and_destroying_objects.html">
            
                <a href="../dynamic_qml/creating_and_destroying_objects.html">
            
                    
                    创建与销毁对象（Creating and Destroying Objects）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.14.2.1" data-path="../dynamic_qml/dynamically_loading_and_instantiating_items.html">
            
                <a href="../dynamic_qml/dynamically_loading_and_instantiating_items.html">
            
                    
                    动态加载和实例化项（Dynamically Loading and Instantiating Items）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.14.2.2" data-path="../dynamic_qml/dynamically_instantiating_items_from_text.html">
            
                <a href="../dynamic_qml/dynamically_instantiating_items_from_text.html">
            
                    
                    从文本中动态实例化项（Dynamically Instantiating Items from Text）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.14.2.3" data-path="../dynamic_qml/managing_dynamically_created_elements.html">
            
                <a href="../dynamic_qml/managing_dynamically_created_elements.html">
            
                    
                    管理动态创建的元素（Managing Dynamically Created Elements）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.14.3" data-path="../dynamic_qml/tracking_dynamic_objects.html">
            
                <a href="../dynamic_qml/tracking_dynamic_objects.html">
            
                    
                    跟踪动态对象（Tracking Dynamic Objects）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.14.4" data-path="../dynamic_qml/summary.html">
            
                <a href="../dynamic_qml/summary.html">
            
                    
                    总结（Summary）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.15" data-path="../javascript/">
            
                <a href="../javascript/">
            
                    
                    JavaScript
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.15.1" data-path="../javascript/browserhtml_vs_qtquickqml.html">
            
                <a href="../javascript/browserhtml_vs_qtquickqml.html">
            
                    
                    浏览器/HTML与QtQuick/QML对比（Browser/HTML vs QtQuick/QML）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.15.2" data-path="../javascript/the_language.html">
            
                <a href="../javascript/the_language.html">
            
                    
                    JavaScript语法（The Language）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.15.3" data-path="../javascript/js_objects.html">
            
                <a href="../javascript/js_objects.html">
            
                    
                    JS对象（JS Objects）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.15.4" data-path="../javascript/creating_a_js_console.html">
            
                <a href="../javascript/creating_a_js_console.html">
            
                    
                    创建JS控制台（Creating a JS Console）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.16" data-path="../qt_and_c++/">
            
                <a href="../qt_and_c++/">
            
                    
                    Qt and C++
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.16.1" data-path="../qt_and_c++/a_boilerplate_application.html">
            
                <a href="../qt_and_c++/a_boilerplate_application.html">
            
                    
                    演示程序（A Boilerplate Application）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.16.2" data-path="../qt_and_c++/the_qobject.html">
            
                <a href="../qt_and_c++/the_qobject.html">
            
                    
                    Qt对象（The QObject）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.16.3" data-path="../qt_and_c++/build_systems.html">
            
                <a href="../qt_and_c++/build_systems.html">
            
                    
                    编译系统（Build Systems）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.16.3.1" data-path="../qt_and_c++/qmake.html">
            
                <a href="../qt_and_c++/qmake.html">
            
                    
                    QMake
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.16.3.2" data-path="../qt_and_c++/cmake.html">
            
                <a href="../qt_and_c++/cmake.html">
            
                    
                    CMake
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.16.4" data-path="../qt_and_c++/common_qt_classes.html">
            
                <a href="../qt_and_c++/common_qt_classes.html">
            
                    
                    Qt通用类（Common Qt Classes）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.16.4.1" data-path="../qt_and_c++/qstring.html">
            
                <a href="../qt_and_c++/qstring.html">
            
                    
                    QString
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.16.4.2" data-path="../qt_and_c++/sequential_containers.html">
            
                <a href="../qt_and_c++/sequential_containers.html">
            
                    
                    顺序容器（Sequential Containers）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.16.4.3" data-path="../qt_and_c++/associative_containers.html">
            
                <a href="../qt_and_c++/associative_containers.html">
            
                    
                    组合容器（Associative Containers）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.16.4.4" data-path="../qt_and_c++/file_io.html">
            
                <a href="../qt_and_c++/file_io.html">
            
                    
                    文件IO（File IO）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.16.5" data-path="../qt_and_c++/models_in_c++.html">
            
                <a href="../qt_and_c++/models_in_c++.html">
            
                    
                    C++数据模型（Models in C++）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.16.5.1" data-path="../qt_and_c++/a_simple_model.html">
            
                <a href="../qt_and_c++/a_simple_model.html">
            
                    
                    一个简单的模型（A simple model）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.16.5.2" data-path="../qt_and_c++/more_complex_data.html">
            
                <a href="../qt_and_c++/more_complex_data.html">
            
                    
                    更复杂的数据（More Complex Data）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.16.5.3" data-path="../qt_and_c++/dynamic_data.html">
            
                <a href="../qt_and_c++/dynamic_data.html">
            
                    
                    动态数据（Dynamic Data）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.16.5.4" data-path="../qt_and_c++/advanced_techniques.html">
            
                <a href="../qt_and_c++/advanced_techniques.html">
            
                    
                    进阶技巧（Advanced Techniques）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.17" data-path="../extending_qml_with_c++/">
            
                <a href="../extending_qml_with_c++/">
            
                    
                    C++扩展QML（Extending QML with C++）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.17.1" data-path="../extending_qml_with_c++/understanding_the_qml_run-time.html">
            
                <a href="../extending_qml_with_c++/understanding_the_qml_run-time.html">
            
                    
                    理解QML运行环境（Understanding the QML Run-time）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.17.2" data-path="../extending_qml_with_c++/plugin_content.html">
            
                <a href="../extending_qml_with_c++/plugin_content.html">
            
                    
                    插件内容（Plugin Content）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.17.3" data-path="../extending_qml_with_c++/creating_the_plugin.html">
            
                <a href="../extending_qml_with_c++/creating_the_plugin.html">
            
                    
                    创建插件（Creating the plugin）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.17.4" data-path="../extending_qml_with_c++/fileio_implementation.html">
            
                <a href="../extending_qml_with_c++/fileio_implementation.html">
            
                    
                    FileIO实现（FileIO Implementation）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.17.5" data-path="../extending_qml_with_c++/using_fileio.html">
            
                <a href="../extending_qml_with_c++/using_fileio.html">
            
                    
                    使用FileIO（Using FileIO）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.17.5.1" data-path="../extending_qml_with_c++/the_application_window.html">
            
                <a href="../extending_qml_with_c++/the_application_window.html">
            
                    
                    应用程序窗口（The Application Window）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.17.5.2" data-path="../extending_qml_with_c++/using_actions.html">
            
                <a href="../extending_qml_with_c++/using_actions.html">
            
                    
                    使用动作（Using Actions）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.17.5.3" data-path="../extending_qml_with_c++/formatting_the_table.html">
            
                <a href="../extending_qml_with_c++/formatting_the_table.html">
            
                    
                    格式化表格（Formatting the Table）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.17.5.4" data-path="../extending_qml_with_c++/reading_data.html">
            
                <a href="../extending_qml_with_c++/reading_data.html">
            
                    
                    读取数据（Reading Data）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.17.5.5" data-path="../extending_qml_with_c++/writing_data.html">
            
                <a href="../extending_qml_with_c++/writing_data.html">
            
                    
                    写入数据（Writing Data）
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.17.5.6" data-path="../extending_qml_with_c++/finishing_touch.html">
            
                <a href="../extending_qml_with_c++/finishing_touch.html">
            
                    
                    收尾工作（Finishing Touch）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.17.6" data-path="../extending_qml_with_c++/summary.html">
            
                <a href="../extending_qml_with_c++/summary.html">
            
                    
                    总结（Summary）
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.18" data-path="../other/">
            
                <a href="../other/">
            
                    
                    其它（Other）
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="1.18.1" data-path="../other/assets.html">
            
                <a href="../other/assets.html">
            
                    
                    示例源码
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.18.2" data-path="../other/enginsh_to_chinses.html">
            
                <a href="../other/enginsh_to_chinses.html">
            
                    
                    术语英汉对照表
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.18.3" data-path="../other/book_format.html">
            
                <a href="../other/book_format.html">
            
                    
                    格式定义
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.18.4" data-path="../other/collaboration_correction.html">
            
                <a href="../other/collaboration_correction.html">
            
                    
                    协作校正
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    

    

    <li class="divider"></li>

    <li>
        <a href="https://www.gitbook.com" target="blank" class="gitbook-link">
            Published with GitBook
        </a>
    </li>
</ul>


                </nav>
            
        
    </div>

    <div class="book-body">
        
            <div class="body-inner">
                
                    

<div class="book-header" role="navigation">
    

    <!-- Title -->
    <h1>
        <i class="fa fa-circle-o-notch fa-spin"></i>
        <a href=".." >HTML5画布移植（Porting from HTML5 Canvas）</a>
    </h1>
</div>




                    <div class="page-wrapper" tabindex="-1" role="main">
                        <div class="page-inner">
                            
<div id="book-search-results">
    <div class="search-noresults">
    
                                <section class="normal markdown-section">
                                
                                <h1 id="html5&#x753B;&#x5E03;&#x79FB;&#x690D;&#xFF08;porting-from-html5-canvas&#xFF09;">HTML5&#x753B;&#x5E03;&#x79FB;&#x690D;&#xFF08;Porting from HTML5 Canvas&#xFF09;</h1>
<ul>
<li><p><a href="https://developer.mozilla.org/en/Canvas_tutorial/Transformations" target="_blank">https://developer.mozilla.org/en/Canvas_tutorial/Transformations</a></p>
</li>
<li><p><a href="http://en.wikipedia.org/wiki/Spirograph" target="_blank">http://en.wikipedia.org/wiki/Spirograph</a></p>
</li>
</ul>
<p>&#x79FB;&#x690D;&#x4E00;&#x4E2A;HTML5&#x753B;&#x5E03;&#x56FE;&#x50CF;&#x5230;QML&#x753B;&#x5E03;&#x975E;&#x5E38;&#x7B80;&#x5355;&#x3002;&#x5728;&#x6210;&#x767E;&#x4E0A;&#x5343;&#x7684;&#x4F8B;&#x5B50;&#x4E2D;&#xFF0C;&#x6211;&#x4EEC;&#x9009;&#x62E9;&#x4E86;&#x4E00;&#x4E2A;&#x6765;&#x79FB;&#x690D;&#x3002;</p>
<p><strong>&#x87BA;&#x65CB;&#x56FE;&#x5F62;&#xFF08;Spiro Graph&#xFF09;</strong></p>
<p>&#x6211;&#x4EEC;&#x4F7F;&#x7528;&#x4E00;&#x4E2A;&#x6765;&#x81EA;Mozila&#x9879;&#x76EE;&#x7684;&#x87BA;&#x65CB;&#x56FE;&#x5F62;&#x4F8B;&#x5B50;&#x6765;&#x4F5C;&#x4E3A;&#x6211;&#x4EEC;&#x7684;&#x57FA;&#x7840;&#x793A;&#x4F8B;&#x3002;&#x539F;&#x59CB;&#x7684;HTML5&#x4EE3;&#x7801;&#x88AB;&#x4F5C;&#x4E3A;&#x753B;&#x5E03;&#x6559;&#x7A0B;&#x53D1;&#x5E03;&#x3002;</p>
<p>&#x4E0B;&#x9762;&#x662F;&#x6211;&#x4EEC;&#x9700;&#x8981;&#x4FEE;&#x6539;&#x7684;&#x4EE3;&#x7801;&#xFF1A;</p>
<ul>
<li><p>Qt Quick&#x8981;&#x6C42;&#x5B9A;&#x4E49;&#x53D8;&#x91CF;&#x4F7F;&#x7528;&#xFF0C;&#x6240;&#x4EE5;&#x6211;&#x4EEC;&#x9700;&#x8981;&#x6DFB;&#x52A0;var&#x7684;&#x5B9A;&#x4E49;&#xFF1A;</p>
<pre><code>for (var i=0;i&lt;3;i++) {
  ...
}
</code></pre></li>
<li><p>&#x4FEE;&#x6539;&#x7ED8;&#x5236;&#x65B9;&#x6CD5;&#x63A5;&#x6536;Context2D&#x5BF9;&#x8C61;&#xFF1A;</p>
<pre><code>function draw(ctx) {
  ...
}
</code></pre></li>
<li><p>&#x7531;&#x4E8E;&#x4E0D;&#x540C;&#x7684;&#x5927;&#x5C0F;&#xFF0C;&#x6211;&#x4EEC;&#x9700;&#x8981;&#x5BF9;&#x6BCF;&#x4E2A;&#x87BA;&#x65CB;&#x9002;&#x914D;&#x8F6C;&#x6362;&#xFF1A;</p>
<pre><code>ctx.translate(20+j*50,20+i*50);
</code></pre></li>
</ul>
<p>&#x6700;&#x540E;&#x6211;&#x4EEC;&#x5B9E;&#x73B0;onPaint&#x64CD;&#x4F5C;&#x3002;&#x5728;onPaint&#x4E2D;&#x6211;&#x4EEC;&#x8BF7;&#x6C42;&#x4E00;&#x4E2A;context&#xFF0C;&#x5E76;&#x4E14;&#x8C03;&#x7528;&#x6211;&#x4EEC;&#x7684;&#x7ED8;&#x5236;&#x65B9;&#x6CD5;&#x3002;</p>
<pre><code>    onPaint: {
        var ctx = getContext(&quot;2d&quot;);
        draw(ctx);
    }
</code></pre><p>&#x4E0B;&#x9762;&#x8FD9;&#x4E2A;&#x7ED3;&#x679C;&#x5C31;&#x662F;&#x6211;&#x4EEC;&#x4F7F;&#x7528;QML&#x753B;&#x5E03;&#x79FB;&#x690D;&#x7684;&#x87BA;&#x65CB;&#x56FE;&#x5F62;&#x3002;</p>
<p><img src="http://qmlbook.org/_images/spirograph.png" alt=""></p>
<p><strong>&#x53D1;&#x5149;&#x7EBF;&#xFF08;Glowing Lines&#xFF09;</strong></p>
<p>&#x4E0B;&#x9762;&#x6709;&#x4E00;&#x4E2A;&#x66F4;&#x52A0;&#x590D;&#x6742;&#x7684;&#x79FB;&#x690D;&#x6765;&#x81EA;W3C&#x7EC4;&#x7EC7;&#x3002;<a href="http://www.w3.org/TR/2dcontext/#examples" target="_blank">&#x539F;&#x59CB;&#x7684;&#x53D1;&#x5149;&#x7EBF;</a>&#x6709;&#x4E9B;&#x5F88;&#x4E0D;&#x9519;&#x7684;&#x5730;&#x65B9;&#xFF0C;&#x8FD9;&#x4F7F;&#x5F97;&#x79FB;&#x690D;&#x66F4;&#x52A0;&#x5177;&#x6709;&#x6311;&#x6218;&#x6027;&#x3002;</p>
<p><img src="http://qmlbook.org/_images/html_glowlines.png" alt=""></p>
<pre><code>&lt;!DOCTYPE HTML&gt;
&lt;html lang=&quot;en&quot;&gt;
&lt;head&gt;
    &lt;title&gt;Pretty Glowing Lines&lt;/title&gt;
&lt;/head&gt;
&lt;body&gt;

&lt;canvas width=&quot;800&quot; height=&quot;450&quot;&gt;&lt;/canvas&gt;
&lt;script&gt;
var context = document.getElementsByTagName(&apos;canvas&apos;)[0].getContext(&apos;2d&apos;);

// initial start position
var lastX = context.canvas.width * Math.random();
var lastY = context.canvas.height * Math.random();
var hue = 0;

// closure function to draw
// a random bezier curve with random color with a glow effect
function line() {

    context.save();

    // scale with factor 0.9 around the center of canvas
    context.translate(context.canvas.width/2, context.canvas.height/2);
    context.scale(0.9, 0.9);
    context.translate(-context.canvas.width/2, -context.canvas.height/2);

    context.beginPath();
    context.lineWidth = 5 + Math.random() * 10;

    // our start position
    context.moveTo(lastX, lastY);

    // our new end position
    lastX = context.canvas.width * Math.random();
    lastY = context.canvas.height * Math.random();

    // random bezier curve, which ends on lastX, lastY
    context.bezierCurveTo(context.canvas.width * Math.random(),
    context.canvas.height * Math.random(),
    context.canvas.width * Math.random(),
    context.canvas.height * Math.random(),
    lastX, lastY);

    // glow effect
    hue = hue + 10 * Math.random();
    context.strokeStyle = &apos;hsl(&apos; + hue + &apos;, 50%, 50%)&apos;;
    context.shadowColor = &apos;white&apos;;
    context.shadowBlur = 10;
    // stroke the curve
    context.stroke();
    context.restore();
}

// call line function every 50msecs
setInterval(line, 50);

function blank() {
    // makes the background 10% darker on each call
    context.fillStyle = &apos;rgba(0,0,0,0.1)&apos;;
    context.fillRect(0, 0, context.canvas.width, context.canvas.height);
}

// call blank function every 50msecs
setInterval(blank, 40);

&lt;/script&gt;
&lt;/body&gt;
&lt;/html&gt;
</code></pre><p>&#x5728;HTML5&#x4E2D;&#xFF0C;context2D&#x5BF9;&#x8C61;&#x53EF;&#x4EE5;&#x968F;&#x610F;&#x5728;&#x753B;&#x5E03;&#x4E0A;&#x7ED8;&#x5236;&#x3002;&#x5728;QML&#x4E2D;&#xFF0C;&#x53EA;&#x80FD;&#x5728;onPaint&#x64CD;&#x4F5C;&#x4E2D;&#x7ED8;&#x5236;&#x3002;&#x5728;HTML5&#x4E2D;&#xFF0C;&#x901A;&#x5E38;&#x8C03;&#x7528;setInterval&#x4F7F;&#x7528;&#x8BA1;&#x65F6;&#x5668;&#x89E6;&#x53D1;&#x7EBF;&#x6BB5;&#x7684;&#x7ED8;&#x5236;&#x6216;&#x8005;&#x6E05;&#x5C4F;&#x3002;&#x7531;&#x4E8E;QML&#x4E2D;&#x4E0D;&#x540C;&#x7684;&#x64CD;&#x4F5C;&#x65B9;&#x6CD5;&#xFF0C;&#x4EC5;&#x4EC5;&#x53EA;&#x662F;&#x8C03;&#x7528;&#x8FD9;&#x4E9B;&#x51FD;&#x6570;&#x4E0D;&#x80FD;&#x5B9E;&#x73B0;&#x6211;&#x4EEC;&#x60F3;&#x8981;&#x7684;&#x7ED3;&#x679C;&#xFF0C;&#x56E0;&#x4E3A;&#x6211;&#x4EEC;&#x9700;&#x8981;&#x901A;&#x8FC7;onPaint&#x64CD;&#x4F5C;&#x6765;&#x5B9E;&#x73B0;&#x3002;&#x6211;&#x4EEC;&#x4E5F;&#x9700;&#x8981;&#x4FEE;&#x6539;&#x989C;&#x8272;&#x7684;&#x683C;&#x5F0F;&#x3002;&#x8BA9;&#x6211;&#x4EEC;&#x770B;&#x770B;&#x9700;&#x8981;&#x6539;&#x53D8;&#x54EA;&#x4E9B;&#x4E1C;&#x897F;&#x3002;</p>
<p>&#x4FEE;&#x6539;&#x4ECE;&#x753B;&#x5E03;&#x5143;&#x7D20;&#x5F00;&#x59CB;&#x3002;&#x4E3A;&#x4E86;&#x7B80;&#x5355;&#xFF0C;&#x6211;&#x4EEC;&#x4F7F;&#x7528;&#x753B;&#x5E03;&#x5143;&#x7D20;&#xFF08;Canvas&#xFF09;&#x4F5C;&#x4E3A;&#x6211;&#x4EEC;QML&#x6587;&#x4EF6;&#x7684;&#x6839;&#x5143;&#x7D20;&#x3002;</p>
<pre><code>import QtQuick 2.0

Canvas {
   id: canvas
   width: 800; height: 450

   ...
}
</code></pre><p>&#x4EE3;&#x66FF;&#x76F4;&#x63A5;&#x8C03;&#x7528;&#x7684;setInterval&#x51FD;&#x6570;&#xFF0C;&#x6211;&#x4EEC;&#x4F7F;&#x7528;&#x4E24;&#x4E2A;&#x8BA1;&#x65F6;&#x5668;&#x6765;&#x8BF7;&#x6C42;&#x91CD;&#x65B0;&#x7ED8;&#x5236;&#x3002;&#x4E00;&#x4E2A;&#x8BA1;&#x65F6;&#x5668;&#x89E6;&#x53D1;&#x95F4;&#x9694;&#x8F83;&#x77ED;&#xFF0C;&#x5141;&#x8BB8;&#x6211;&#x4EEC;&#x53EF;&#x4EE5;&#x6267;&#x884C;&#x4E00;&#x4E9B;&#x4EE3;&#x7801;&#x3002;&#x6211;&#x4EEC;&#x65E0;&#x6CD5;&#x544A;&#x8BC9;&#x7ED8;&#x5236;&#x51FD;&#x6570;&#x54EA;&#x4E2A;&#x64CD;&#x4F5C;&#x662F;&#x6211;&#x60F3;&#x89E6;&#x53D1;&#x7684;&#xFF0C;&#x6211;&#x4EEC;&#x4E3A;&#x6BCF;&#x4E2A;&#x64CD;&#x4F5C;&#x5B9A;&#x4E49;&#x4E00;&#x4E2A;&#x5E03;&#x5C14;&#x6807;&#x8BC6;&#xFF0C;&#x5F53;&#x91CD;&#x65B0;&#x7ED8;&#x5236;&#x8BF7;&#x6C42;&#x65F6;&#xFF0C;&#x6211;&#x4EEC;&#x8BF7;&#x6C42;&#x4E00;&#x4E2A;&#x64CD;&#x4F5C;&#x5E76;&#x4E14;&#x89E6;&#x53D1;&#x5B83;&#x3002;</p>
<p>&#x4E0B;&#x9762;&#x662F;&#x7EBF;&#x6BB5;&#x7ED8;&#x5236;&#x7684;&#x4EE3;&#x7801;&#xFF0C;&#x6E05;&#x5C4F;&#x64CD;&#x4F5C;&#x7C7B;&#x4F3C;&#x3002;</p>
<pre><code>...
property bool requestLine: false

Timer {
    id: lineTimer
    interval: 40
    repeat: true
    triggeredOnStart: true
    onTriggered: {
        canvas.requestLine = true
        canvas.requestPaint()
    }
}

Component.onCompleted: {
    lineTimer.start()
}
...
</code></pre><p>&#x73B0;&#x5728;&#x6211;&#x4EEC;&#x5DF2;&#x7ECF;&#x6709;&#x4E86;&#x544A;&#x8BC9;onPaint&#x64CD;&#x4F5C;&#x4E2D;&#x6211;&#x4EEC;&#x9700;&#x8981;&#x6267;&#x884C;&#x54EA;&#x4E2A;&#x64CD;&#x4F5C;&#x7684;&#x6307;&#x793A;&#x3002;&#x5F53;&#x6211;&#x4EEC;&#x8FDB;&#x5165;onPaint&#x5904;&#x7406;&#x6BCF;&#x4E2A;&#x7ED8;&#x5236;&#x8BF7;&#x6C42;&#x65F6;&#xFF0C;&#x6211;&#x4EEC;&#x9700;&#x8981;&#x63D0;&#x53D6;&#x753B;&#x5E03;&#x5143;&#x7D20;&#x4E2D;&#x7684;&#x521D;&#x59CB;&#x5316;&#x53D8;&#x91CF;&#x3002;</p>
<pre><code>Canvas {
    ...
    property real hue: 0
    property real lastX: width * Math.random();
    property real lastY: height * Math.random();
    ...
}
</code></pre><p>&#x73B0;&#x5728;&#x6211;&#x4EEC;&#x7684;&#x7ED8;&#x5236;&#x51FD;&#x6570;&#x5E94;&#x8BE5;&#x50CF;&#x8FD9;&#x6837;&#xFF1A;</p>
<pre><code>onPaint: {
    var context = getContext(&apos;2d&apos;)
    if(requestLine) {
        line(context)
        requestLine = false
    }
    if(requestBlank) {
        blank(context)
        requestBlank = false
    }
}
</code></pre><p>&#x7EBF;&#x6BB5;&#x7ED8;&#x5236;&#x51FD;&#x6570;&#x63D0;&#x53D6;&#x753B;&#x5E03;&#x4F5C;&#x4E3A;&#x4E00;&#x4E2A;&#x53C2;&#x6570;&#x3002;</p>
<pre><code>function line(context) {
    context.save();
    context.translate(canvas.width/2, canvas.height/2);
    context.scale(0.9, 0.9);
    context.translate(-canvas.width/2, -canvas.height/2);
    context.beginPath();
    context.lineWidth = 5 + Math.random() * 10;
    context.moveTo(lastX, lastY);
    lastX = canvas.width * Math.random();
    lastY = canvas.height * Math.random();
    context.bezierCurveTo(canvas.width * Math.random(),
        canvas.height * Math.random(),
        canvas.width * Math.random(),
        canvas.height * Math.random(),
        lastX, lastY);

    hue += Math.random()*0.1
    if(hue &gt; 1.0) {
        hue -= 1
    }
    context.strokeStyle = Qt.hsla(hue, 0.5, 0.5, 1.0);
    // context.shadowColor = &apos;white&apos;;
    // context.shadowBlur = 10;
    context.stroke();
    context.restore();
}
</code></pre><p>&#x6700;&#x5927;&#x7684;&#x53D8;&#x5316;&#x662F;&#x4F7F;&#x7528;QML&#x7684;Qt.rgba()&#x548C;Qt.hsla()&#x3002;&#x5728;QML&#x4E2D;&#x9700;&#x8981;&#x628A;&#x53D8;&#x91CF;&#x503C;&#x9002;&#x914D;&#x5728;0.0&#x5230;1.0&#x4E4B;&#x95F4;&#x3002;</p>
<p>&#x540C;&#x6837;&#x5E94;&#x7528;&#x5728;&#x6E05;&#x5C4F;&#x51FD;&#x6570;&#x4E2D;&#x3002;</p>
<pre><code>function blank(context) {
    context.fillStyle = Qt.rgba(0,0,0,0.1)
    context.fillRect(0, 0, canvas.width, canvas.height);
}
</code></pre><p>&#x4E0B;&#x9762;&#x662F;&#x6700;&#x7EC8;&#x7ED3;&#x679C;&#xFF08;&#x76EE;&#x524D;&#x6CA1;&#x6709;&#x9634;&#x5F71;&#xFF09;&#x7C7B;&#x4F3C;&#x4E0B;&#x9762;&#x8FD9;&#x6837;&#x3002;</p>
<p><img src="http://qmlbook.org/_images/glowlines.png" alt=""></p>
<p>&#x67E5;&#x770B;&#x4E0B;&#x9762;&#x7684;&#x94FE;&#x63A5;&#x83B7;&#x5F97;&#x66F4;&#x591A;&#x7684;&#x4FE1;&#x606F;&#xFF1A;</p>
<ul>
<li><p><a href="http://www.w3.org/TR/2dcontext/" target="_blank">W3C HTML Canvas 2D Context Specification</a></p>
</li>
<li><p><a href="https://developer.mozilla.org/en/HTML/Canvas" target="_blank">Mozilla Canvas Documentation</a></p>
</li>
<li><p><a href="http://www.html5canvastutorials.com/" target="_blank">HTML5 Canvas Tutorial</a></p>
</li>
</ul>

                                
                                </section>
                            
    </div>
    <div class="search-results">
        <div class="has-results">
            
            <h1 class="search-results-title"><span class='search-results-count'></span> results matching "<span class='search-query'></span>"</h1>
            <ul class="search-results-list"></ul>
            
        </div>
        <div class="no-results">
            
            <h1 class="search-results-title">No results matching "<span class='search-query'></span>"</h1>
            
        </div>
    </div>
</div>

                        </div>
                    </div>
                
            </div>

            
                
                <a href="canvas_paint.html" class="navigation navigation-prev " aria-label="Previous page: 画布绘制（Canvas Paint）">
                    <i class="fa fa-angle-left"></i>
                </a>
                
                
                <a href="../particle_simulations/" class="navigation navigation-next " aria-label="Next page: 粒子模拟（Particle Simulations）">
                    <i class="fa fa-angle-right"></i>
                </a>
                
            
        
    </div>

    <script>
        var gitbook = gitbook || [];
        gitbook.push(function() {
            gitbook.page.hasChanged({"page":{"title":"HTML5画布移植（Porting from HTML5 Canvas）","level":"1.8.9","depth":2,"next":{"title":"粒子模拟（Particle Simulations）","level":"1.9","depth":1,"path":"particle_simulations/README.md","ref":"particle_simulations/README.md","articles":[{"title":"概念（Concept）","level":"1.9.1","depth":2,"path":"particle_simulations/concept.md","ref":"particle_simulations/concept.md","articles":[]},{"title":"简单的模拟（Simple Simulation）","level":"1.9.2","depth":2,"path":"particle_simulations/simple_simulation.md","ref":"particle_simulations/simple_simulation.md","articles":[]},{"title":"粒子参数（Particle Parameters）","level":"1.9.3","depth":2,"path":"particle_simulations/particle_parameters.md","ref":"particle_simulations/particle_parameters.md","articles":[]},{"title":"粒子方向（Directed Particle）","level":"1.9.4","depth":2,"path":"particle_simulations/directed_particle.md","ref":"particle_simulations/directed_particle.md","articles":[]},{"title":"粒子画笔（Particle Painter）","level":"1.9.5","depth":2,"path":"particle_simulations/particle_painter.md","ref":"particle_simulations/particle_painter.md","articles":[]},{"title":"粒子控制（Affecting Particles）","level":"1.9.6","depth":2,"path":"particle_simulations/affecting_particles.md","ref":"particle_simulations/affecting_particles.md","articles":[]},{"title":"粒子组（Particle Group）","level":"1.9.7","depth":2,"path":"particle_simulations/particle_group.md","ref":"particle_simulations/particle_group.md","articles":[]},{"title":"总结（Summary）","level":"1.9.8","depth":2,"path":"particle_simulations/summary.md","ref":"particle_simulations/summary.md","articles":[]}]},"previous":{"title":"画布绘制（Canvas Paint）","level":"1.8.8","depth":2,"path":"canvas_element/canvas_paint.md","ref":"canvas_element/canvas_paint.md","articles":[]},"dir":"ltr"},"config":{"gitbook":"*","theme":"default","variables":{},"plugins":[],"pluginsConfig":{"highlight":{},"search":{},"lunr":{"maxIndexSize":1000000,"ignoreSpecialCharacters":false},"sharing":{"facebook":true,"twitter":true,"google":false,"weibo":false,"instapaper":false,"vk":false,"all":["facebook","google","twitter","weibo","instapaper"]},"fontsettings":{"theme":"white","family":"sans","size":2},"theme-default":{"styles":{"website":"styles/website.css","pdf":"styles/pdf.css","epub":"styles/epub.css","mobi":"styles/mobi.css","ebook":"styles/ebook.css","print":"styles/print.css"},"showLevel":false}},"structure":{"langs":"LANGS.md","readme":"README.md","glossary":"GLOSSARY.md","summary":"SUMMARY.md"},"pdf":{"pageNumbers":true,"fontSize":12,"fontFamily":"Arial","paperSize":"a4","chapterMark":"pagebreak","pageBreaksBefore":"/","margin":{"right":62,"left":62,"top":56,"bottom":56}},"styles":{"website":"styles/website.css","pdf":"styles/pdf.css","epub":"styles/epub.css","mobi":"styles/mobi.css","ebook":"styles/ebook.css","print":"styles/print.css"}},"file":{"path":"canvas_element/html5porting_from_html5_canvas.md","mtime":"2021-05-30T14:00:07.439Z","type":"markdown"},"gitbook":{"version":"3.2.3","time":"2021-05-30T14:16:45.097Z"},"basePath":"..","book":{"language":""}});
        });
    </script>
</div>

        
    <script src="../gitbook/gitbook.js"></script>
    <script src="../gitbook/theme.js"></script>
    
        
        <script src="../gitbook/gitbook-plugin-search/search-engine.js"></script>
        
    
        
        <script src="../gitbook/gitbook-plugin-search/search.js"></script>
        
    
        
        <script src="../gitbook/gitbook-plugin-lunr/lunr.min.js"></script>
        
    
        
        <script src="../gitbook/gitbook-plugin-lunr/search-lunr.js"></script>
        
    
        
        <script src="../gitbook/gitbook-plugin-sharing/buttons.js"></script>
        
    
        
        <script src="../gitbook/gitbook-plugin-fontsettings/fontsettings.js"></script>
        
    

    </body>
</html>

